


A Little Edge

by ImaginationBubbles



Category: Undertale (Video Game)
Genre: ABDL, Age Play, Age Regression/De-Aging, Alternate Universe - Underfell (Undertale), Big Brother Sans (Undertale), Diapers, Diapertale, Fluff, Hurt/Comfort, M/M, Mentions of dusting and underfell angst, Omorashi, Underfell Papyrus (Undertale), Underfell Sans (Undertale), Watersports, Wetting, can be read as platonic or relationship, idc whatever floats your boat
Language: English
Status: In-Progress
Published: 2020-11-14
Updated: 2021-01-01
Packaged: 2021-03-10 01:07:18
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 8,490
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27565747
Author URL: https://archiveofourown.org/users/ImaginationBubbles/pseuds/ImaginationBubbles
Summary: Red has an idea for how to get his workaholic brother to relax. To heal some of the trauma they're both carrying around. One day, he finally gets his chance.Edge is confused as all hell, but at least the diapers are comfortable.
Relationships: Fellbros - Relationship, Fellcest, Papyrus & Sans, Underfell Sans/Underfell Papyrus
Comments: 41
Kudos: 47





	1. Becoming Little

“Sans, this is ridiculous.”'

“Call it what ya’ want, boss. A deal’s a deal.”

Edge scowled at the box. When he lost that bet, he'd thought Red would invent something devious, true ― but not so disturbed.

“I― no. No.”

“Yes. Get changed.

Edge cringed and closed the box, hiding the horrible outfit. He’d wear a sexy maid dress, a clown suit, fucking anything other than this.

But he’d given his word, and goddamn it, that meant something to him. Defeat was the only thing that might hurt his pride worse than what Sans wanted him to do.

“No photos,” he growled, stomping up the stairs.

“Not if you’re good,” Red shouted after him, smugness in his voice. Edge slammed the door and threw the box against the wall, contents flopping out. The soft pink fabric of oversized infant clothing stood out like a sore thumb against the dark colors of his room.

The thing was silly, like a one-piece bathing suit made of satin. Next to it, a white lump glared from the floor. The lieutenant of the royal guard was going to wear a cutesy diaper costume. Disgraceful.

Buckles and straps on his battle body unclipped one by one. Edge took all the time he could to strip down to bare bones. He rattled from what he determined was a draft and not nerves. Edge spread the white pad open and tried to tape up the diaper on his waist while standing. Securing the padding was harder than he thought. He fumbled countless times before giving up and laying on the floor.

The diaper was snug on his hips and soft on his bottom. He wasn’t used to being comfortable, preferring the cold steel of protective armor. Edge stuck each leg through the holes in the onesie and pulled it up. He had to wonder where Red had found it. This wasn’t from the dump. It had to have been an expensive special order. Or maybe, even worse, Red had made it for him by hand.

The mirror didn’t need to face Edge to tell him what he looked like. A six-foot-tall adult monster standing in a baby’s outfit. He’d probably die if he saw it.

Edge flopped on the ground, refusing to move until Red got his ass upstairs and demanded it. He said he’d wear it, nothing else. But waiting left him with nothing to focus on but the strange sensations of his clothing. It was warm, but with his legs bare, not terribly so. It felt like sitting on a pillow with all that padding.

“Papyrus? You done?”

Finally, Edge had to meet the executioner. There was no way to go about this with dignity, so he kept his head low as he swung the door open. Staring down at his feet, he couldn’t see the expression on Red’s face.

“You look good,” Red said, and Edge wanted to smash his skull in. “Now come downstairs.”

With an eye roll, Edge shoved past his brother when a hand on his wrist stopped him. “What?!” he jerked, tearing out of Red’s grip.

“You have to let me carry you,” Red said.

“I have to― I can walk.”

“Babies can’t walk, and today you’re my baby brother. So unless you’d rather crawl, get your ass on the ground.” Red snapped his fingers, pointing down at the floor.

Edge considered. Crawling was the more humiliating option, and it wouldn’t be comfortable on the stairs. With his luck he’d fall over, snap his neck, and Red would bury him like this. Apparently he took too long to decide, because Edge didn’t get a warning before he rose into the air. “Hey-!” Caught off guard by the unexpected strength his lazy brother showed off, Edge flailed.

“Oof- calm down. I’ve carried you loads before.”

“Not in― not in twenty years! How are you even doing this?”

“C’mon bro, you’re all skin and bones.” The little shit grinned at Edge as he walked down the stairs. It was strange. Once he was able to manage it himself, Edge would take all of Red’s responsibilities. If he could walk, no more piggy back rides. When Edge learned to cook? Red never made him a meal again. It had been decades since he’d decided he was too old to be held, but he remembered this. A tiny, faded memory still existed.

Red sat him on the floor, which groused him. Not even on the couch. “I got you presents,” Red said, bending down to face him. He reached into one of his jacket’s unnumbered hidden pockets and rustled around in it. “What’s this? An old friend!” He pulled out a limp, raggedy stuffed bunny. Unlike the clothing, it was clearly second hand, worn down and faded. Edge grimaced as Red dropped it in front of him.

“It’s ugly,” he sneered. Red’s smile wilted as if he was actually hurt. How ridiculous. Huffing, Edge pinched it and picked it up like a piece of trash and Red perked up.

“Good boy,” he hummed, patting Edge on the head until sharp teeth snapped at his fingers, forcing him to pull away. “Now what else do we have here?” Red dug into his coat again and produced a shiny little thing. It fit in the palm of his hand, and at first Edge didn’t know what it was until Red tried to push it in his mouth.

“Fuck off.” Edge slapped the pacifier back, clamping his teeth shut tight.

 _“Yes,"_ Red insisted, eyebrows raised. His body language was relaxed, but the warning in his tone stung.

Edge felt the burn of tears welling up in his skull. He couldn’t remember the last time he cried, but he was about to. Defeated, he opened his mouth obediently and held the rubbery pacifier.

Shaking with frustration, Edge glared at the floor. He tried to shove his embarrassment deep down into his chest like he always did. The painful vulnerability of the situation he was in made it impossible. He unsuccessfully tried to fight back tears.

“Aww, poor thing. Don’t cry.”

Edge blinked and jerked back from Red. He tried to scramble away, but Red grabbed him and dragged him up his chest.

It was warm. Bones weren’t soft, yet it was easy to relax into the hold. His eyes slipped closed as he leaned on Red for support. Now that he was calm, he became aware of his crippling exhaustion. He’d been working long hours recently, but had felt no effects until this very moment. His bones ached so much. He didn’t think he could walk away if he wanted to. Could his legs support him?

Red rocked Edge from side to side as his breathing softened out. The pacifier was still in his mouth, and he couldn’t help but tongue the soft nipple. It was soothing. Everything about this scenario was like walking through a long-forgotten building. Mental ghosts were rising, flickers of memories. He’d sucked his thumb as a baby, hadn’t he? And when he felt scared, he’d rock himself like this.

“There, there. Isn’t this nice?”

Edge’s feelings were beyond confused. He was expecting mockery, but Red was taking this seriously. Red picked him up and carried him again, this time to the kitchen where he pulled two baby bottles from the fridge. Edge stared at it with a slow-building sense of dread. He couldn’t imagine what was in them.

“You’ll like it,” Red said, as if he’d already tried it. They went back to the couch― was he so easy to carry?― and sat down. Edge shifted in Red’s lap. He felt like a doll, moved around and posed however Red wanted. “Open up,” Red said, tugging the pacifier out.

“I am not bottle-feeding,” Edge protested. Yet he opened his mouth for it. It was pathetic, but his brother had him trapped. He held the nipple in his mouth, refusing to drink. An impatient Red squeezed the bottle and shot milk down his throat. He gagged violently, sputtering the drink back up.

“Oops. Guess you better suck it,” Red said, flexing his fingers around the bottle threateningly.

Sucking the bottle felt less ridiculous than struggling at this point. It was like giving in felt, somehow, like the mature decision.

The milk was cold and sweet. He did like it, how thick and creamy it was. His hands curled in his brother's leather jacket. When Red started rubbing his back, his eyes fell closed again. This affection was addicting, like the first time he ever slept on a bed instead of the hard ground outside. He sank into it, amazed at how good it felt.

"You want more? Hungry boy," Red cooed, and Edge realized he'd been mouthing the nipple of the now-empty bottle. He'd finished it all? Hadn't it only been a second?

Red turned him over his shoulder, thumping his ribs. The pressure was so unexpected Edge couldn't hold back a bubble of gas, liquid dribbling out of his mouth. He cringed in disgust. His body kept betraying him. It was like he had no control over his reactions. But his brother didn’t care. He wasn’t grossed out and didn’t laugh at him, no matter what shameful thing he did. The acceptance was heady like a drug.

Case in point, when Red brought another bottle, he let it in with little coaxing. Suddenly he was starving, so it didn’t matter. When did he last eat? He nearly choked from drinking too quickly. His doubts and insecurities seemed to disappear with every gulp.

A full stomach was bliss. He let Red burp him. He didn't fight Red bringing him back into a hug. His body was loose and warm, his stomach tingling.

"Such a good boy. You want your bunny?" Red picked the little rabbit up and pressed it against Edge’s face.

Edge tried to turn away, but then a familiar smell caught his attention, and memories flooded back.

_“Don’t worry, I’ll be back- Papyrus, let go of my arm. I can’t stay with you all day.”_

_“I know you’re scared to be alone, but this little guy will keep you company, okay?”_

_“What do you want to name him?”_

“B- B- Bee- Bam....” Edge’s mouth moved clumsily, trying to rediscover long-lost muscle memory. “Bumb... Bumby?”

His hands were shaking-- no, all of him was shaking as he hugged the stuffed bunny tight to his chest. He buried his nose in the fur, breathing in deep. “Bumby,” he repeated, voice cracking. “S- Sans, it’s Bumby,” he said like his brother wasn’t the one to give it to him.

“You remember now,” Red said, smiling wide. “Took me ages to stitch him back up. Kept the scraps until I learned how to sew… finally got around to it.”

Edge wasn’t paying attention to a thing Red was saying. He squeezed his stuffed bunny as hard as he could, and he cried, silent tears turning into hiccuping sobs. He hadn’t cried since he was a babybones, and now he was wailing and stumbling over broken thank you’s to his brother. Red had fixed Bumby.

The memory was still burned in his mind. The way he clawed at the other children, desperate to get back the only thing in the world he owned. His pathetic pleas for mercy drowned out by their laughter. The sharp rip of fabric tearing.

His first lessons in cruelty and weakness.

But Bumby was here. Edge hadn’t lost him forever, he was okay and Edge was okay too. He threw his arms around Red’s neck, still heaving.

“S- S- Sans-”

“I know, shh, I know.”

“Bumby!”

“It is Bumby, huh?” Red chuckled, “You happy?”

“Yes,” Edge said earnestly, sniffling, drowning in confusing sensations. The diaper felt good. The outfit too. He’d embarrassed himself and he didn’t give a single fuck because he was happier than he could ever remember being. He felt safe. Relaxing completely into his big brother’s arms, Edge closed his eyes and let the wonderful feelings wash over him.

“If you’re feeling up to it, then, I’d like to try something else.”

Edge snorted. “Now you’re asking permission?” he asked dryly, and Red flushed.

“I don’t wanna hurt ya. When I gave you all of this,” he motioned to the outfit, “I knew you’d be fine afterwards.”

“And I might not be okay after this?”

“I think you’ll be great. That’s what this all is for.” Red adjusted Edge in his lap into a more comfortable position.

Edge tilted Bumby’s head up, looking him over. The stitching job was remarkable. Red had taken care to get everything just right for him.

“I want to,” he said.

“Good.” Red squeezed him. “Can you make your body for me, please?”

Edge was taken aback. “You mean― all of it?”

“At least your torso.”

“But I just finished the milk.” His body wasn’t finished converting it to magic yet. If he summoned his body now, the energy would need a place to go. His organs would start working.

“That’s the idea, sweetheart.” Red kissed him. Edge’s eyes widened. Red wanted him to―

“No way, absolutely not.”

“You said you’d try. You don’t go back on your word, yeah?”

Edge whimpered, unconsciously squeezing his legs together. “I― I feel like,” he stuttered, struggling to find the words, “like if I do it I'll be gross, and you’ll never respect me or like me and―”

“Hey, hey.” Red pressed the pacifier back into his mouth. “No. Stop that right now. I will always like you and respect you. Nothing will change that. I wanna do this because I think it’ll help you. Hell, I respect you more now. You’ve done such a good job, been such a good brave boy for me.”

Edge took the pacifier. It felt nice to not have to worry about what to say next, if he’d fuck it up or not. Not every sentence had to be perfect. He didn’t have to do anything but play with his binkie.

It didn’t take long for him to decide. Bright red ecto magic filled out the onesie and stretched the diaper, making it crinkle. He wanted to be a brave boy. Red’s hands rubbed his stomach as it started to gurgle.

He’d never noticed Red’s hands before. Even if Red was shorter than him, his hands were significantly bigger than Edge’s thinner ones.

“That’s my good boy.”

Edge purred under the attention. He loved it when his brother’s focus was all on him. For once, it wasn’t violent or fearful. He found he liked this much more.

“Yeah, that’s good. You probably need more milk, huh?”

Edge whined, grabbing onto Red’s jacket with both fists. Red needed to stay with him. He wasn’t allowed to leave. But Red didn’t make a move to stand. Instead blue magic opened the fridge and levitated a bottle straight to them.

Since when did Red have the control or power to do that? But then his pacifier was replaced, and he had other things to worry about, like draining his bottle dry of milk.

The milk made him purr as it filled him up. Maybe it was because he hadn’t eaten anything else today, and the easy calories satisfied his stomach. With the extra liquid his stomach quickly bulged out, a heavy weight settling into the bottom of his guts. It didn’t feel bad. It was warm and tingly. But it reminded him of what was coming.

“Hol’ me,” he said softly, tugging Red closer. He pressed his knees to his chest, trying to shrink down smaller so Red could wrap his arms all the way around him. He buried his face in his brother’s shoulder, smelling the spicy mustard and magic there. It was wonderful.

He’d only been getting hugs for a few minutes, and he couldn’t stop. He wanted to be squeezed tight and never let go. Focusing on breathing in Red’s scent, he almost missed when it started. The tingles rose to a prickling pain.

He didn’t have any practice trying to hold, but he clenched his muscles down tight out of reflex. “Let go,” Red whispered, rocking him side to side. So he did.

It was warm, relief flooding over him. The noises coming from between his legs made him blush. And it was heavy, a weight sagging down on his pelvis.

“You cryin’, baby?” Red asked softly, brushing away the tears trickling down Edge’s face. He hadn’t noticed, but he was. He started to cry again, bones rattling as he fell completely apart.

His big brother was still there. After everything Edge had done, he was still there by his side. It was wonderful. It was exhausting.

“Are you alright?” Red's voice faded in and out. It was hard to focus on anything. When Edge tried to respond, he gurgled. "Aww, yes you are. Baby sleepy?"

Edge never felt tired, but he caught himself fading in and out of consciousness. Big hands massaged his stomach. It felt so nice. Curled up in a pair of strong arms, he went limp like a puppet with cut strings. "Snnn..." he sighed, trying to pull together a coherent thought.

Big brother made him feel so good. His paci was slipped into his mouth and he sucked on it, hands latching onto the fur of Red’s jacket. “I love you so much,” Red cooed.

Edge felt himself moved around, legs spread open. Shivering as a draft hit his thighs, the tugs of what could only be a diaper change. “Bih… boh-derr…” Edge slurred, fading quickly as he was cleaned and secured in a new puffy cushion. A blanket draped over him was all it took to send him to dreamtown.

―

Red could never have imagined this going so well. He stroked his little brother’s skull as he slept for the first time in a week. All he’d hoped for was getting Edge fed and relaxed for an evening. Now he had endless plans for the future swirling in his head. But at the moment, all he wanted was to curl up behind Edge, kiss his forehead, and settle down for a nice nap.


	2. Good Days and Bad

**Summary for the Chapter:**

> Some days are good, some are bad. They're together through it all.

Red was in the kitchen cooking when the door creaked open. 6:10 on the dot. The nights he "made dinner" were usually takeout, but this time he was throwing half the fridge into a stew. Somehow, unlike his brother's meals, most things he made turned out fine in the end.

The sound of heels thumping up the stairs made him shout, "Shoes off in the house!" The stomping came back down, accompanied by grumbling. Red knew Edge was tucking his stilettos neatly in place by the door. Then he heard Edge run into his room, footfalls softened to socks on carpet.

Chuckling, Red shook his head, taking his time to chop the carrots.s

"Saaaans!"

"Don't yell at me from through the door.”.

Edge peeked out of his room. "Hurry up."

"Food takes time, bro. You can start without me." Red knew what the response would be, but it still made him smile.

"No. I can't do it myself. You gotta." Edge pouted and stomped his foot, Red noting the display. He must already be slipping into headspace.

"Okay, okay, big brother is coming, hold your horses." Red turned the stove down to low before going up to his brother's room. Edge was bouncing in his seat on the bed, the supplies for the evening carefully chosen and laid out beside him.

Red took Edge's shirt in his hands, tugging it up. The routine was new, but they already had it memorized. He peeled off the layers of armor until Edge was bare bones. Then he folded and stacked the uniform away, careful not to damage it. The point of this was to make les stress for his brother, after all, not more.

Edge tried to crawl to the other end of the bed, giggling as he tried to escape under the covers. Red snagged Edge's ankle and tugged him back into place, flipping him over. Red grinned and tickled his ribs, provoking a shriek. "Wow, you're excitable today. Gonna make me work extra hard, huh?"

Edge hid his face behind his hands, smiling widely at the teasing. Red took the opportunity to lift Edge's hips up, tucking a diaper under his pelvis. When he hit the padding, Edge relaxed so much that he went limp on the mattress.

Red liked this part. When Edge’s eyelights expanded, hazing out into fuzzy ovals. The color was between crimson and pink, and he loved it. It was physical evidence of how fully Edge had let go, how deeply he trusted Red to catch him when he fell.

Red taped it closed and patted him on the bum, turning to the outfit Edge had picked out. The first one was hard enough to get, and this wasn't the sort of wardrobe they could walk into a store and buy for. He'd turned to making most of the articles of clothing himself.

This white onesie was simple, but one of Edge's favorites for the addition of a fake cat tail and a hood with ears. 

Red tugged the fabric over Edge's head, meeting the wide, shining smile of his baby brother. It was the smile of someone who was completely vulnerable and fearless, because he trusted his big brother to protect him. Red felt his heart clench.

"I think you deserve a treat for being so good," he said, because Edge was always good and always deserved treats. 

Edge's whole face lit up and he nodded like a bobble head. "I was super good! Me and Undyne got stuck behind a waterfall-" and he was chattering on about his day. Red let him babble on, half-listening as he carried him down the stairs.

Red sat Edge on the couch, leaving him with Bumby to chew on while he got their dinner ready. He was sure to include a cookie for the treat he’d promised. No matter how Edge tried, he couldn't only live off bottles while he was little.

Red put the food on the coffee table and offered a spoon to Edge, who popped his bunny out of his mouth to look offended. "No."

"You can't feed yourself?" Red's sharp mouth tugged into a smirk. He loved doing everything for Edge. They both knew he relished hearing the other declare his helplessness.

"You know I can't. I'm just a little baby." Edge stuck out his tongue, and Red chuckled.

"My little baby." He picked up the bib he brought in with the napkins and tied it around Edge's neck. He scooped a nice spoonful of stew for him, blowing on it before offering it up. "Here comes the airplane," he sing-songed.

Edge opened his mouth, clearly holding back a laugh at the absurdity. Soon he’d eaten and was watching a dvd of old human cartoons Red dug out of the dump. Red had his own meal before it got cold, and when he set his bowl down Edge took the cue to clamber into his open lap.

“Bum, bum, bum, Bumbyyy fwy, he fwy up high~” Edge sang as he spun his stuffie in the air, leaning against his caregiver’s chest. 

“You’re talkin’ pretty small now, luv,'' Red observed, discreetly checking Edge’s diaper. Still clean. That meant he’d need to wear the diaper to bed tonight, which meant he’d be waking up in headspace. Red would have to call them in for a late start to work.

Red wished Edge could go to bed and wake up in diapers every day if that’s what he wanted. But for now they would keep it locked away, carefully hidden from the harsh world outside. The battle-scarred warrior had his brother to take care of his needs in private.

“Small!” Edge said, popping his thumb in his mouth, something he did on his own when he felt particularly young. “Can you show me how old you are?” Red wiggled his fingers at Edge, who hummed and shrugged. He silently held up two fingers. Red kissed them both, making the padded one giggle.

Two years old. They were quickly discovering that the younger Edge was allowed to be, the happier he was. Edge curled up in Red’s arms, trying to climb into his jacket. Red chuckled and tugged over the throw blanket from the other end of the couch. “No nap time,” he warned, “or you’ll never get to sleep tonight.” Who knew it would ever be Red keeping Edge awake.

Edge nodded, keeping his focus on the TV while they cuddled, stuffed animal securely held in his arms. “Later I wanna do coloring.”

“Alright.”

“And I want to make a pillow fort.”

“Whatever you want.” Red rubbed Edge’s skull, ruffling non-existent hair. Edge batted the hand away, laughing. Red would give him the world if it kept that smile on his face.

* * *

It was 6:30 and there was no reason to panic. Red knew that anything could make Edge 20 minutes late. Any number of plausible, safe possibilities. He already had the burgers from Grillby’s reheating in the oven. Edge loved Grillby’s food when he was little.

Edge’s pacifier and bottles were clean and drying next to the sink. He set out the diaper changing station. He was running out of things to do and ways to keep his anxiety at bay. Red stumbled back into the kitchen, using a dish towel to mop up the sweat on his skull. 6:35. Who was he kidding, the shaking in his hands and labored breathing were getting out of control. He needed his brother home and in his arms right fucking _now._

When the door clicked open, he nearly had a heart attack. Taking a deep breath, he closed his eyes and smiled, listening for the usual banging. He had to be calm to keep from worrying Edge.

But there was nothing. No sound. No feet pattering down the hall, no shouting or cursing or laughter. Red’s stomach dropped. He looked around the corner.

Edge was sitting on the floor, head in his knees, hugging himself. Red studied the scene before him. There was dust and blood spattering Edge’s clothes. Luckily there was no sign of the aggressive, manic energy of an LV rush. 

So it was going to be a bad day. Red shuffled up, tapping Edge’s knee to let him know he was there. A brief movement, but no real reaction. Red unzipped Edge’s boots and set them aside, lifting the other monster into his arms. 

It forced Edge to face him, and Red wanted to cry at how empty he was. Gutted sockets, expressionless, and hollow. Red kissed his forehead.

Edge wouldn’t want to get dust on his baby things. Red took him to the bathroom first, setting Edge on the toilet and running the water for a bath. That would help.

“I’m gonna start undressing you, okay?” Red announced. He wasn’t sure if Edge could see him, or if he was lost in his own head. He received no reaction from the other skeleton. 

“I’m grabbing your belt. I’m unbuckling it. I’m pulling off your leather pants. The seat will be cold.” Red narrated everything before he did it, keeping his voice steady. “Now the armor is going by the door where it won’t get wet. I’m folding your shirt so it doesn't wrinkle.”

Red added bubbles to the tub so Edge wouldn’t see the dust in the water. When it was ready, he picked Edge up again and slowly lowered him in. “Now we can get nice and clean.” 

He washed Edge down with a rag, talking to him as if nothing was wrong. His little brother still wasn’t saying anything. He kept his position curled in on himself. Red wiped every bone, getting into every nook and cranny so there would be no graininess between the joints.

“Pappy, can you move for me? Show me if you’re here with me. I know talking is hard right now.” Red rinsed more dust into the water. It’d be hell to unclog their drain later. Edge’s eyes fell closed and then opened again. A blink. Red would take it.

“Good boy! You’re such a good boy,” Red praised, running the rag over Edge’s leg. He hoped the sensation of being pet was grounding. Pulling the plug, he lifted Edge back out, bundling him in a towel. He grunted from the strain. He could carry his brother fine, but he was dead weight like this. He needed some blue magic to make it all the way to the bedroom.

He laid Edge on the bed, caressing his cheek as he dressed him up like a doll. “We get to put our pjs on early, don’t we? Yeah, that’s fun. Pajama day.” 

First the diaper, and he got a response from Edge when he put it on. A jolt, almost like a flinch, but with no intent to move away. And maybe Edge uncurled from himself a little.

Red picked out a onesie with feet attached. He was zipping it when Edge grabbed his wrist. Red glanced up and saw his sockets still black, but tears were forming in the empty holes.

After the dissociation came the emotional storm. Red squeezed Edge’s hand, reminding him that he would be there to weather it with him.

A whimper. Then a gasp. He turned and buried his face in the mattress, sobs muffled so no one would hear and hurt him for showing weakness. Red turned him over, cradling him against his shoulder.

“Cry it all out. It’s alright now,” Red said, wincing at the agony in his Pappy’s voice. His chest shook, unable to get enough air. 

Red held him closer. “I love you so much. You’re so loved. You’re not a bad person. You’re safe now.” Red whispered reassurances until Edge was silent again. 

Red untucked Edge’s face from his neck to look at him. His eyelights were back, but they were pinpricks, darting around looking for threats. Red had to work quick before a full-blown panic attack or flashback started.

“Dinner time.” Red knew Edge wouldn’t eat, but the structure was familiar and would help. Structure was good. Structure kept them sane. 

Despite feeling like crap himself, Red hummed a cheerful tune as he wrapped Edge’s legs around his waist and lifted him. He let out a little sigh of relief as Edge was conscious enough to hold himself up now. 

Downstairs, he turned off the oven on the way to the couch. They spent most of their days there, cuddled together every night. 

Red set Edge down there, pushing the coffee table close to work as an eating surface. His best bet for getting Edge to eat would be a bottle of milk. At least it was something. He made two plates of food for them anyway, to give him the option. 

Before they’d started their sessions, he’d have thrown his own meal out and gone to bed to hide from the stress. But he couldn’t. He had to set a good example and take care of himself if he wanted to help Pap. So he scarfed down the food, ignoring his rolling stomach and focusing on finishing as much as he could.

His body was grateful for the energy rush, and he ate more fries than he thought he would. Putting his plate down, he turned his attention back to the skeleton laying on his side. Red maneuvered Edge into his lap, bringing the bottle to his mouth and holding it ready for him. “Can you give me one suck? One is all I need to see.” 

Sometimes it only took a bit of coaxing to start Edge drinking properly. Today, he barely managed to put his mouth around the bottle without Red’s help. 

Red waited, staying still as the minutes ticked by. Finally Edge sucked his cheeks in, taking a mouthful of the creamy milk.

“Amazing. What a star.” Red pet Edge’s skull as he drained the bottle. Thirty minutes later he was patting Edge’s back, cooing at him. “There we go. Hard bit is over.” He laid down between his brother and the back of the couch, spooning him from behind.

“Now we get to watch TV and snuggle.” Red flipped the channel to one of Mettaton’s shows. There wasn’t any point in searching for anything better to put on. Edge would be flickering in and out of focus anyway.

The light from the windows was dim when a rustling noise woke Red. The soft couch and drone of the TV had put him to sleep. He yawned, stretching out and checking for his brother. Edge was turning around, trying to bury his face in Red’s chest.

Hugging the younger close, Red caught a glimpse of his expression. It was teary-eyed and unhappy, but there was magic dusting his cheeks again. He was moving and reacting, clearly back in his body. 

“Hey baby,” Red said, keeping his voice low, so he wouldn't startle Edge. The other still flinched a little, but wrapped his arms around his brother tighter.

Red hummed and ran his hand down Edge’s spine. Judging by the fresh tear marks and wet spots on his pajamas, Edge had had another cry.

“Would it help to talk about it?” Red wasn’t surprised by the frantic head shaking. “That’s fine. We could distract you with a game, or do some coloring-”

“Sans.” Red paused, holding his breath. It wouldn’t be strange for Edge to spend all night mute, unable to speak even if he wanted to. 

“Yes, baby?”

“Please hold me.”

Red let out a breath he didn’t know he was holding. He nodded, laying down and letting Edge cling to him. Soon they’d need to get a blanket, or go to bed, and if he was feeling better Edge should probably try eating again-

A soft sigh brushed those thoughts away. Right now all they had to do was stay together.

“Thank you, Sansy,” Edge said, voice muffled in Red’s jacket. Red knew he meant for everything. For the gentle touches, the bath, the chance to be with each other like this.

“You’re very welcome,” Red said, yawning. There would be nightmares tonight, almost certainly, but the worst was over. They’d made it through, survived another day in a world threatening constantly to break them. Red stroked a finger on Edge’s cheek. He wouldn’t let it. There was something deep in his soul burning to fight and protect.

If monsters could feel such a thing, he’d say he was filled with determination.

**Notes for the Chapter:**

> Whooo! Next chapter! Finals ended and I got right to work. A day in the life of these two. A fun day and a day when the world hurts more than usual. I wanted to show both what their new normal is, now that Red introduced this therapy play, and how badly it's needed.
> 
> I'll figure out what a linear plot is someday... someday... (-.- ) it was fun to write from Red's perspective this time.
> 
> I can't believe how many people read and left kudos! Please enjoy this chapter too ♥


	3. A Lovely Outing

**Summary for the Chapter:**

> Their games end up spreading outside the house, and it's new and exciting and wonderful. Things go awry.

**Notes for the Chapter:**

> Heavy watersports in this chapter, fair warning

“Papyrus.” 

“Captain.” Edge saluted his leader from behind his sentry station. His back was ramrod straight as he stood at attention, like always, but she frowned at him.

“You’ve changed.” 

He twitched as she looked him up and down. It was obvious what she was talking about. Underneath the light battle armor, his normal top was replaced with a shirt that went far past his waist.

“Yes, ma’am.”

“It looks ridiculous.”

“It’s- it’s laundry day. The welp forgot to wash my usual uniform. I apologize, my esteemed captain.” He bowed stiffly and then yelped as she pulled him into a noogie that almost burned a hole through his skull.

“Undyyyyne!”

“Fuckin nerd, don’t ‘esteemed captain’ me, I’ll beat the crap out of you!”

Edge thrashed, aiming a kick for her shins, grinning as she let him go with a grunt. 

They were the closest thing to friends you could get in the underground. They’d known each other since they were nothing but rats on the streets. She’d always been a berserker with violent tendencies, and he’d always been, in her words, ‘A massive punk bitch’.

“Where is your brother, anyway? If he’s wandered off, it’ll come out of your paycheck.”

Edge shrugged. “He’s making his rounds in the upper forest. He’ll be back soon I’m sure.”

“He better be.” Undyne flipped him off as she walked away, and he gave her a return bird until she was out of sight. 

Dropping his hand, he heaved a sigh of relief, plopping his ass down in his chair. He winced at the crinkling sound.

“Aww, you didn’t snitch on me. Thanks little boss.” Red emerged from his hiding spot under the sentry station.

“You’re not even supposed to be here, idiot!” Edge snapped, shifting around in his seat. It was like sitting on a hidden pillow.

“But who else is gonna take care of you?” Red cooed, tugging at Edge’s overly long shirt. Damn thing was nearly a dress, but it was necessary to hide how his crotch puffed out.

“I― I don’t need to be taken care of, and keep your voice down―!” Edge was suddenly turned over his sentry station, ass in the air, hands braced against the table. 

“Sans!” he exclaimed, struggling as his brother pulled his pants down. “Stop, not here. Are you crazy? Someone’s gonna see!”

“No one is gonna see. I looked around first.” Red pulled the hem of his diaper back, and Edge shrieked, “No, no, no―”

“If you don’t stop throwing a fit, I’ll extend the time we’re doing this. And do I have to remind you why you’re in this position in the first place?” Red popped Edge on the bottom. Lightly, a warning tap, but it made Edge settle down so Red could do what he needed to.

“Because I…” Edge trailed off, mumbling.

“Because you?”

“Don’t make me say,” Edge pleaded, hiding his face.

Red was merciful and said it for him. “Because someone insisted that they didn’t need a diaper before bedtime. Threw a whole tantrum and then wet the bed. And lied about it.” Red gave Edge a thorough once-over, inspecting him closely.

Edge’s was bright crimson. They were in the middle of the forest, and if anyone found them, they’d see him like this. Pants around his knees, diaper out, and big brother scolding him.

It made his soul race. It was amazing. He wasn’t little, too on-guard to fall into headspace, but the feelings were twice as exciting. Everything was heightened to a new level.

“Take your thumb out of your mouth, sweetheart.”

Edge blinked in surprise, pulling the appendage out and wiping the saliva on his sleeve. When did that happen?

Well, maybe he was feeling a tad little.

“Can I get back to work now?” Edge struggled to keep the whine out of his voice. Red shook his head, tugging at his hips. “Turn over, you need a change.”

“That’s impossible.”

Red shrugged. “Well, you do. “

“No, I do not.” Edge reached back, awkwardly groping at his ass until Red took his hand and guided it to show him.

Oh. That was wet. Not about to leak, but very noticeably wet. “I didn’t even feel it,” he said to himself, shocked. He moved his hand away quickly.

“I think Undyne scared the piss out of you, heh.” Red lifted him fully on the sentry station. Instead of the usual weapons or alcohol, there was a pack of clean diapers hidden underneath. 

Edge grimaced as his damp pelvis was exposed to the cold winter air. While there was a risky charm to their makeshift changing table, he missed his pacifier and toys. This was boring and uncomfortable.

He entertained himself by complaining while Red shifted the old diaper out for a new one. “This wouldn’t have happened if you hadn’t given me soup for breakfast today. You made way too much, and now we have to have leftovers every meal.”

Red paused and looked incredulously at him. “You said it was your favorite, and you wanted to eat it every day forever.”

“Yeah, so?”

Rolling his eyes, Red taped the diaper nice and snug, just the way Edge liked it. Then he pulled Edge’s thumb back out of his mouth. Oops.

“I need you to be honest with me right now,” Red said, the humor fading out of his eyes. 

Like a switch flipped, the mood changed. Edge’s face fell. Maybe he crossed a boundary without meaning to.

“Did you really not notice you went?” Red buttoned up Edge’s pants, pulling him into his lap.

Oh, was that all? Smiling again, Edge nodded, but Red kept frowning. 

“When you started wetting the bed, it was on purpose. You’d wake up at night and decide to―”

“Sans, no!” Edge cut that talk off right there. That wasn’t something to be explained out loud. 

It was true, but his brother didn’t need to say it.

“―but now you’re using your diapers in the middle of the day, without even realizing. Are you in pain? I know an infection could change things.” Red ran a status check on him, and Edge shook his head, huffing. 

“Quit your fussing and fretting, brother. I am healthy.”

“But―”

“I’m sure it’s nothing,” Edge brushed him off. “I haven’t had this function for long enough to know what’s normal.”

“It’s something to think about. When you wet the bed last night, it seemed like it was a real accident with all the crying, so―”

Before Red could embarrass him further, Edge stood off the other’s lap and started walking. “This is ridiculous. I am going to do my job, something I would advise you to consider doing as well.”

Red got up quickly, reaching out for Edge as he moved away. “Hold on, you were just changed. You need to be watched for a while before you can wander off―”

Edge stuck his nose up. “You think I can’t handle myself? And may I remind you,” he cut Red off before he could argue, “it was your idea to put me in these things during guard duty. Excuse me for being the responsible one and actually continuing to work despite that.” Head held high, Edge started on his route. He’d show him. Everything was fine.

* * *

Everything was not fine.

Edge had barely made it out of sight of his brother when he felt a familiar tingle in his gut. Of course, he couldn’t turn around and ask for another change after marching off so proudly. It was a manner of honor.

To his credit, he held it as long as he could. Normally his route took an hour to travel. But he spent half that time leaned against a tree, hands stuffed between his legs, until he had to admit defeat.

He closed his eyes as he let go. Warmth flooded his trousers. He was used to this happening in cotton clothes that would shift and expand with him. These pants were stiff and unyielding.

Something running down his leg made him flinch and clench up in horror. Oh fuck. Oh no. He was leaking. A dark patch was quickly spreading over his pants, staining them.

He tried to cross his legs and stop it, but lost his balance and fell on his ass, crying out as piss seeped down his thighs. There was too much, the diaper couldn’t hold. 

Edge swore with every drop that ran out of him, he could feel his brain draining out too. His adult head was slipping through his fingers like sand. Everything felt foggy and far-away the way it did when he was in littlespace. 

Everything suddenly seemed so big. The trees loomed over his head, casting long shadows on the ground.

He wept, crouched in his puddle. Alone, in the middle of the woods, completely vulnerable to attack. He was already curled into the fetal position. A diaper leak put his mind in a fragile state. All of a sudden he was no bigger than a toddler.

He wasn’t used to being little without his big brother nearby. Red always came rushing to save Edge when he cried, armed with bandaids and snacks and kisses to heal any ill.

Still sobbing, Edge tried and failed to stand up. These were very difficult shoes, throwing him completely off balance. He fell back into the snow, unable to keep himself upright. 

Stuffing his thumb back in his mouth, because he needed it right now, he tried to figure out what to do. Big brother always said if he was lost or hurt to wait for him, and this was kind of like that.

(Later, he would understand he could have dialed Red on the phone, or taken his shoes off and stumbled back to him. But he wasn’t thinking clearly, or at all.)

So Edge stayed. As snow began to fall and cover him, he shivered, feeling disgusting and dirty. Why hadn’t big brother found him yet? Maybe he hadn’t been gone long enough for him to worry.

Or maybe Red realized Edge was too violent and needy to be worth keeping around― 

“Darling, here. I told you I smelled something funny.” 

Edge went stiff as a shuffling noise came from the forest behind him. Pressed against the tree bark, he tried to make himself as small as possible. He struggled to summon his attack magic. It slipped out of his grasp when he was little, soul rebelling against the idea of violence.

“I know what you mean. Where is it?” The noise was drawing closer. Edge held his breath and waited. He recognized those voices. He could hear something heavy dragging in the snow. He imagined a battle axe, stained with blood―

A big wet nose shoved in his face made him squeak, falling back on his ass.

“Dogamy, look, we found it!”

“Is it a smell to eliminate?”

“Smell, what are you?”

Edge rolled on the ground, trying and failing to scramble to his feet. Dogamy and Dogaressa were fierce warriors, though no match for him normally. But this was not normally. He’d been so stupid, and now they were going to know his secret and tell everyone in the guard.

Dogamy leaned down and a big pink tongue licked the side of his head. “It smells like a puppy. Where did you come from, little pup?”

Edge froze, still on his knees. He smelled… like a puppy? He should smell like piss and dirt.

Come to think of it, that was probably what a puppy smelled like.

Letting out a shaky breath, Edge kept silent. The dogs couldn’t see him very well at all, only smell and hear him. As long as he didn’t talk, they couldn’t tell it was him. And if he smelled like a dog, they wouldn’t hurt him, right?

“It’s okay, little doggy. You’re safe with us.” He’d never seen Dogaressa look like that. Usually she was snarling or glaring, but right now her expression was gentle and warm. She pet a hand over his head.

“I bet you’re a very good dog. I know it’s scary, but we’re part of the guard. We’re here to help.”

Edge whimpered, leaning into the touch. It was scary. And he did know where his m- big brother was, but he couldn’t walk there. He started to cry again, stress bubbling up.

“Don’t cry! Please don’t cry puppy. I promise we’ll find your mommy. Can you tell us where she is?” Dogamy asked, kneeling down low so he didn’t overwhelm the frightened creature.

Edge hiccupped and pointed to the direction he’d come from. The movement must have been enough for the dogs’ weak eyes to track, because they sniffed along the trail.

“There, there, it’s alright now. Can you walk?” More pets from the Dogaressa.

Edge had been incredibly lucky, but crawling back behind two of his coworkers wasn’t going to happen. He whined in a way that he hoped conveyed no and curled back up against the tree.

The two whispered between each other before doing something else he’d never seen them do. They split apart, Dogamy following the footprints back in the snow.

“He’ll find her, don’t you worry. My hubby is the best tracker in New Home,” Dogaressa said. Edge whimpered again and sneezed. He’d been out in the frigid snow awhile now. He was shaking, ice setting into his bones.

“Are you cold? It’s alright. I’m here.” A pair of strong, furry arms embraced him, driving the chill back.

Edge had never been hugged by another monster before, only his brother. He leaned into it, craving warmth and comfort. 

He hadn’t thought about smelling someone to learn about them before. Dogs did it all the time, but he’d never paid any attention. Dogaressa smelled of metal polish and blood, like all the guards, but also lavender and bread. Maybe she baked a lot at home. It was a soothing scent.

It didn’t seem like very long at all before he was pulled away. Had he started to doze a little?

“Are you sure you got them, Red?”

“Yeah, I do. Thanks ‘Gamy.”

Edge buried his face in Red’s coat, latching on immediately. He was much calmer now. He closed his eyes, nuzzling into his big brother.

“This chewtoy said he knows where their mother lives,” Dogamy explained to his wife. Edge muffled a laugh at the nickname while Red grunted in offense.

“Let’s bring him there, then.” Edge heard Dogaressa stand, snow crunching beneath her boots.

The jacket shifted as Red shook his head. “No, she, uh, doesn’t like other dogs. But I can take this puppy back home.”

“But she likes you?” Dogaressa snorted. A wet nose nudged at his face, and he turned back as he was sniffed. “Be good, puppy,” the dog lady said, patting his skull. Then she walked away with Dogamy by her side.

“Well, that was a disaster. I’m officially never letting you out of my sight again. Are you alright?” Red took in his full appearance, ruined clothes and hazy eyelights. 

Even as he was, Edge could see past Red’s careless grin. The sweat dripping down his face and the creases at the corners of his eyes betrayed him. His brother was worried to death.

“I’m fine,” Edge answered honestly, leaning into the other so Red could hear his soul beating. When Red looked at him with disbelief, he shrugged.

“She was... nice to me. They both were.” She was like what I imagine a mother would be, he thought. He kept that part to himself. “They confused me for a dog.”

“Yeah, I’m never letting you live that down, by the way.” Red grinned as the hum of magic filled the air. He was gearing up for a teleport. “Do I need to check you for a tail? Or will you sprout fuzzy ears?”

Edge thwacked Sans’s arm as the universe folded in on itself around them and they shortcut home. He knew they’d have a lot to discuss when he was clean and dry, but right now he was happy. His secret was safe, and he was wrapped in his favorite pair of arms.

That night, after an evening of being spoiled and pampered, he was tucked into bed. He should get lost more often. A big brother was a million times cooler than a parent, anyway.

**Notes for the Chapter:**

> Starting off the new year with my least favorite chapter so far. Seriously, I hate this one. I gave up editing halfway through so I can just get to the next. I thought about deleting it, but I didn't write 2800 words for no reason, and there's plot stuff set up here.   
> (￢_￢;) Please stick with me for the next one, I have high hopes for it. 
> 
> You might be thinking, how did Dogaressa not realize when she hugged Edge that this was a bony skeleton and not a fluffy dog? She did. (｡•̀ᴗ-)✧ But she's smart and knows a puppy is a puppy anyway. Plus she knows how to keep her mouth shut.
> 
> Thanks for reading!


End file.
